ML20148H490

Topical Rept Evaluation of Rept Envirostone Gypsum Cement USG-684-1. Rept Acceptable W/Stated Limitations

ML20148H490
Person / Time
Issue date:	03/03/1988
From:	NRC OFFICE OF NUCLEAR MATERIAL SAFETY & SAFEGUARDS (NMSS)
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ML20148H481	List: ML20148H478 ML20148H490
References
REF-WM-51 NUDOCS 8803300004
Download: ML20148H490 (24)

Text

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!. 3 TECHNICALEVA'LUATIONREFORTON10'CFRPARTj'61' REQUIREMENTS ~

- FOR THE TOPICAL REPORT ENTITLED-- _ l ENVIROSTONE GYFSUM CEMElvT ,

USG-684 .i SUBMITTED BY USG COPP0 RATION:

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4- A30 TRACT This Technical Evaluation Report (TER) ha' a been nrepared by the Office of s ' ' 1 Nuclear Materials Safety and Safeguards of the U.S Nuclear Regulatory

' Comission for the topical repo% filed by USG Corporation, covering)itsENVIROSTONE staff concludes that a conditfor11 one year approval be given for the one waste l stream (mixedbedionexchangeresin,60%packingefficiency)thatmeetsall

the specificationt/' stated in the Technical Position on Waste Form. This is based on the uncertainties regardir,g softening of the waste form as discussed in the TER. Acceptance ir! limited to the one waste stream and the conditions stated in this Evaluatice.! report.

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l TABLE OF CONTENTS PAGE ABSTRACT................................................ 2 1 . 0 B AC KG RO U N D . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4 1.1 Re g u l a t i o n s . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4 1.2 Description of the Topical Report............. 4 1.3 Topical Report Submittals..................... 5 2.0

SUMMARY

OF REGULATORY EVALUATION. . . . . . . . . . . . . . . . . . . . . . . . 6 2.1 Minimum Requirements of 10 CFR 61.56(a)....... 6 2.2 Stability Requirements of 10 CFR 61.56(b)..... 7 2.2.1 Structural Stability................... 7 2.2.2 Free Liquid............................ 7 2.2.3 Void Spaces............................ 7 2.3 Recommendations of the Technical Position on Wa s te Fo rm . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8 2.3.1 Compressive Strenq'6................... 8 2.3.2 Radiation Resisti ................... 9 2.3.3 Immersion Resistans .................. 10 2.3.4 Thermal Cycling........................ 11 2.3.5 Biodegradation......................... 12 2.3.5.1 Fungal Growth.............. 12 2.3.5.2 Bacterial Growth........... 14 2.3.6 Leachability Index..................... 16 2.3.7 Free Liquid.............. ............. 18 2.3.8 Ful l Scale Resul ts. . . . . . . . . . . . . . . . . . . . . 19 2.3.9 Homogeneity............................ 19 2.3.10 Process Control Program. . . . . . . . . . . . . . . 19 2.3.11 Cure Condi tions . . . . . . . . . . . . . . . . . . . . . . . 20 3.0 REGULATORY P0SITION..................................... 21

4.0 REFERENCES

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1.0 BACKGROUND

1.1 Regulations By Federal Register Notice dated December 27, 1982 (47 FR 57446), the United States Nuclear Regulatory Comission (NRC) amended its regulations to provide specific requirements for licensing of facilities for the land disposal of icw-level radioactive waste. The majority of these requirements are now contained in Part 61 to Title 10 of the Code of Federal Regulations (10 CFR Part 61) entitled "Licensing Requirments for Land Disposal of Radioactive Waste" (Ref.1). Minor modifications, mostly of a procedural nature, have been made to other parts of the Comission's regulations, such as 10 CFR 20

("Standard for Protection Against Radiation"). These regulations are the culmination of a set of prescribed procedures for low-level radioactive waste disposal that were proposed in the Federal Register on July 24, 1981.

The effective date for the implementation of 10 CFR 20.311, whic.h requires waste generators to meet the waste classification and waste form requirements in 10 CFR Part 61, was December 27, 1983. As set forth in 10 CFR 61.55, Class B and Class C waste must meet structural stability requirements that are established under 10 CFR 61.56(b). In May, 1983 the NRC provided additional guidance by means of a Technical Position on Waste Form (Ref. 2) that indicated that structural stability could be provided by processing (i.e., ,

solidification) the waste form itself f as with large activated steel l component-l or by emplacing the container nr structure that provides stability  ;

(i.e., a high integrity container (HIC))

1.2 Cescription of the Topical Report:

The USG Corporation's topical report for solidification of class B and C waste I streams utilizes a product known as ENVIROSTONE Gypsum Cement. ENVIROSTONE is a finely grcund, non-flamable powder consisting of Calcium Sulfate Hemihydrate binder in conjunction with a polymer. The purpose of the polymer is for interstitial sealing of the waste fann for inhibition of liquid into the l hardenea mass. Ib cddition, for solidification of non-polar organic wastes, I the ENVIROSTONE is used in conjunction with an emulsifier. l The topical report discusses sample preparation and test procedures, test I results, and recommended field precedures. A process tantrol prograo was i submitted as part of the USG respnnse to NRC's questions.

Data were presented in the Topical report on eight waste streams that simulate typical nuclear power plant low level radioactive wastes. These waste streams are:

1. 24% Boric Acid Solutions, up to 78% packing efficiency (Percent by Volume). Full scale 55 gallon drums use 270lbs of ENVIPJ) STONE, and 45 gallons of 24% Boric acid solution.

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2. Unexpended (ion exchange capability remaining) Mixed Bed Ion Exchange Bead Resin (up to 80% packing efficiency by volume). Full scale 55 gallon drums at 80% pM king efficiency use 2151bs of ENVIROSTONE, 2411bs of bend resin and 21 gallons of water.

3. Unexpen: led P6wdered Ian Exchange Resin (up to 83% packing efficiency by volume). Fuli scale 55 gallon drums use 1951bs of ENVIR0 STONE,150lbs of powdered resi:is and 31 gallons of water.

4. Lubricating Oil (up to 50% packing efficiency by volume). Full scale 55 gallon drums use 2241bs of ENVIROSTONE, 3 gallons of ENVIROST0hE emulsifier 27.5 gallons of raste oil and 13 gallons of water.

5. Mixture of Mixed Bed Ion Exchange Bead Resin and 24% Boric Acid solution (80% packing ' efficiency). Full scale 55 gallon drums use 2151bs of ENVIROSTONE, 2411bs of bead resin and 21 gallons of 24% boric acid solution.

6. Mixtures of Powdered Ion Exchange Resins and 24% Boric Acid solution (83% packing efficiency). Full scale 55 gallon drums use 1951bs of ENVIR0 STONE, 150lbs of powdered resin and 31 gallons of 24% boric acid-solution.

7. EDTA decontamination fluid (up to 50% packing efficiency by volume of 50% EDTA solution. Full scale 55 gallon drums use 300lbs of ENVIROSTONE, and 27.5 gallons of EDTA solution.

8. A Neat Aqueous Mixture of ENVIROST0GE Gypsum Cement. Full scala 5F gallon drurs use 300lbs of ENVIROSTONE and 38.5 gallons of water 1.3 Topical Report Submittals The USG Corporation submitted i; heir topical report on ENVIR0 STONE Gypsum Cemenc to the NRC on May 29, 1984 (ref 4). The vendor was notified of the acceptance of the topical report for review on June 28,1984(ref5).

The topical report was distributed for review and coment within the NRC and to  ;

the States of South Carolina and Washington. These two Agreement States have j regulatory responsibility over the low-level waste disposal sites at B6rnwell, 1 SC and Hanford, WA. respectively. Coments transmitted by the State of Washington (ref 8) were incorporated into the review. South Carolina indicated that they had no additional convents (ref 7).

NRC coments were submitted to USG on Sept. 13,1985(ref6).OnNov.8,1985 ,

USG submitted draft responses to our concents and a meeting was held between 1 NRC and USG during November,1985 (ref 9) to discuss NRC's coments. The second response and topical report revision was sent by USG to the NRC on July 2, 1986 (ref 10).

1 A second set of NRC comments was sent to USG on October 27, 1986 (ref 11). The response to those comments was received by the NRC on Jul with supplemente arriving on September 24, 1987 (ref 13)and y 17, 19878,(ref October 12) 1987 (ref 14).

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2.0

SUMMARY

OF REGULfTORY EVALUATION.

The information presented in the topical report and USG's letter responses to the NRC's comments provide the basis for the following evaluation.

2.1 Minimum Requirements of 10 CFR 61.56(a)

a. Packaging The waste form is contained in a steel 55-gallon drum and thus satisfies this requirement.

b. Liquid Waste Liquid wastes are completely solidified in normal operations. This satisfies the requirement of no more than 0.5% by volume of free standing liquid,

c. Free Standing Water The solidification process utilizes a polymer which inhibits the formation of liquid into the hardened .cass. The Process Control Program gives guidance to users of ENVIROSTONE gypsum cement on how to assure a satisfactory solidified waste product. The solidified product is capable of producing waste forms having less than 0.5% free standing liquid,

d. Reactivity of Product ,

After solidification, the waste form produced from the proposed waste streams does not appear to contain any substances capable of explosive '

decomposiition or reactions at normal pressure and temperatures,

e. Gas Generation The solidified waste form does not appear to be capable of generating quantities of toxic gases, vapors or fumes harmful to persons l transpcrting, handling or disposing of the waste form.

f. Pyrophoricity The waste form does not contain materials which are pyrophoric as defined in 10 CFR 61.2.

g. Gaseous wastes  !

This provision is not applicable to ENVIROSTONE.

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h. Hazardous Wastes Undar the Resource Conservation and Recovery Act (RCRA), the U.S. l Environmental Protection Agency (EPA) has jurisdiction over the management l of s6 lid hazardous wastes with the exception of source, byproduct, and special nuclear material, which are regulated by the NRC under the Atomic 6

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Energy Act (AEA). Low-level radioactive wastes (LLW) contain source, byproduct, or special nuclear materials, but they may also contain chemical constituents which are hazardous under EPA regulations promulgated under Subtitle C of RCRA. Such wastes are commonly referred to as Mixed Low-Level Radioactive and Hazardous Waste (Mixed Waste).

Applicable NRC regulations control the byproduct, source, and special nuclear material components of the Mixed LLW (10 CFR Parts 30, 40, 61, and 70); EPA regulations control the hazardous component of the Mixed LLW (40 CFR Parts 260-266, 268 and 270). Thus, all of the individual constituents of Mixed LLW are subject to either NRC or EPA regulations. However, when the components are combined to become Mixed LLW, neither agency has exclusive jurisdiction under current Federal law. This has resulted in dual regulation of Mixed LLW where NRC regulates the radioactive cocponent and EPA regulates the hazardous component of the same vaste.

Under Section 10 CR 61.56(a)(8) waste containing hazardous, biological, pathogenic, or infectious material must be treated to reduce to the maximum extent practicable the potential hazard from the non-radiological materials. The waste form consisting of Envirostone Gypsum Cement plus the waste stream materials listed in Table I of this evaluation does not contain biological, pathogenic or infectious material, and thus satisfies these requirements of 10 CFR Part 61.

It should be noted, however, that the NRC Topical Report review of the Envirostone Gypsum Cement process did not address any applicable EPA requirements relating to hazardous solid' waste for which the vendor or waste generator using the Envirostone Gypsum Cement process for LLW may be legally responsible under RCRA.

2.2 StabilityRequirements_of10CFR61.56(b) 2.2.1 Structural Stability The waste form must exhibit structural stability under expected disposal conditions. Structural stability means that it must generally maintain its physical dimensions and form. Expected disposal conditions include the weight of the overburden and compaction equipment, the presence of moisture and microbial activity, and internal factors such as radiation effects and chemical changes. The solidified product using ENVIROSTONE will be contained in a 55 gallon steel drum, but no credit for stability will be taken for the drum. The evaluation for structural stability is presented in section 2.3.

2.2.2 Free Liquid Water is essentially removed from the waste stream during the solidification of the waste product. No free liquids were observed in the qualification testing. Therefore, the requirement that free liquids be no  !

rrore than 0.5 volume percent of the waste is satisfied. l 2.2.3 Void spaces 7 j i

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l l-Drums containing the waste form will be filled while the waste form is l still. fluid. Solidification then takes place in the container thereby reducing the void spaces between the waste and the container to the extent i practicable. It is the responsibility of the user to ensure that containers are filled to reduce void spaces.

2.3 Reconnendations _of the Technical Position on Waste Form 2.3.1 Compressive strength All of the compressive strength tests were performed on two inch cubes in triplicate based on ASTN C472 "Standard Methods for Physical Testing of Gypsum Plasters and Gypsum Concrete. Initial compressive strength figures were determined for srsples curing in sealed, 4 mil polyethylene bags.

The 1983 Technical Pc,sition on Waste Form recorreended that the minitrun compressive strength for a solidified waste product be at least 50 psi.

The minimum allowab?e compressive strength has subsequently been raised to 60 psi . This was dora in order to take into account the increase of turial loading at hanford from 45 feet to 55 feet. The following is a list of the results of the compressive strength tests at the maximum packing efficiency proposed by USG for the 8 waste streams:

1. 24% Boric Acid Solutions (up to 78% packing efficiency by volune)

Compressive Strength = 389~ psi

2. Unexpended Mixed Bed Ion Exchange Bead Resin (up to 80% packing efficiency by volume)

Compressive Strength = 286 psi

3. Unexpended Powdered Ion Exchange Resin (up to 82% packing efficiency by volume)

Compressive Strength = 267 psi

4. Lubricating 011 (up to 50% packing efficiency by volume)

Compressive Strength = 241 psi

5. Mixture of Mixed Bed Ion Exchange Bead Resin and 24% Boric Acid solution (80% packing efficiency). Full scale 55 gallon drums use 2151bs of ENVIROSTONE, 2411bs of bead resin and 21 gallons of 24% boric acid solution.

Compressive Strength = 198 psi

6. Mixture of Powdered Ion Exchange Resins and 24% Boric Acid solution (83% packing efficiency). Full scale 55 gallon drums use 1951bs of E"VIR0 STONE, 150lbs of powdered resin and 31 gallons of 24% boric acid solution.

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1 l Compressive Strength = 147 psi

7. EDTA decontamination fluid (up to 50% packing efficiency by volume of 50% EDTA solution Compressive Strength = 1870 psi

8. A Neat Aqueous Mixture of ENVIROSTONE Gypsum Cement Compressive Strength = 1555 psi All of the waste streams meet or exceed the 60 psi currently reconwended for waste forms.

2.3.2 Radiation Resistance The radiation exposure evaluations were performed on two inch cubes according to ASTM D1672 "Standard Reconnended Practice for Exposure of Polymeric Materials to High Energy Radiation, Procedure A". The cubes were exposed to a Co60 field with a calculated dose of 100.08 megarads over.a period of 246.1 hours1.157407e-5 days <br />2.777778e-4 hours <br />1.653439e-6 weeks <br />3.805e-7 months <br />. Compressive tests were then performed on the cubes. The compressive strength of the solidified waste form should be at least 60 psi after radiation exposure. The following are the results of the compressive test after radiation exposure for the eight waste streams at the maximum proposed packing efficiencies.

1. 24% Boric Acid Solutions (up to 78% packing efficiency by volume)

Conpressive Strength = 223 psi

2. Unexpended Mixed Bed Ion Exchange Bead Resin (up to 80% packing efficiency by volume)

Compressive Strength = 159 psi

3. Unexpended Powdered Ion Exchange Resin (up to 82% packing efficiency by volume)

Compressive Strength = 186 psi

4. Lubricating Oil (up to 50% packing efficiency by volume)

Compressive Strength = 188 psi

5. Mixtur of Mixed Bed Ion Exchange Bead Resin and 24% Boric Acid solution 80% packing efficiency). Full scale 55 gallon drums use 2151bs of ENVI'.vSTONE, 2411bs of bead resin'and 21 gallons of 24% boric acid solution.

Compressive Strength = 139 psi 9

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6. Mixture of Powdered Ion Exchange Resins and 24% Boric Acid solution (83% packing efficiency). Full scale 55 gallon drums use 1951bs of ENVIROSTONE, 150lbs of powdered resin and 31 gallons of 24% boric acid solution.

Compressive Strength = 88 psi

7. EDTA decontamination fluid (up to 50% packing efficiency by volume of 50% EDTA solution Compressive Strength = 1208 psi

8. A Neat Aqueous Mixture of ENVIROSTONE Gypsum Cement.

Compressive Strength = 1133 psi All of the waste streams meet or exceed the 60 psi currently recomended for waste forms.

2.3.3 Immersion Resistance; The imersion resistance tests were performed on two inch cube samples in triplicate after immersion in tap water for ninety days. At the end of the ninety day period compression tests were performed on the samples. The solidified waste form should have a compressive strength of at least 60 psi af ter immersion in water for ninety days. The following are the results of the compressive tests after the ninety day inmersion test for each of the waste forms at the maximum proposed packing efficiencies.

1. 24% Boric Acid Solutions (up to 78% packing efficiency by volume)

Compressive Strength = 145 psi

2. Unexpended Mixed Bed Ion Exchange Bead Resin (up to 80% packing efficiency by volume)

Compressive Streng*.h =.152 psi

3. Unexpended Powdered Ion Exchange Resin (up to 82% packing efficiency byvolume)

Compressive Strength = 213 psi

4. Lubricating 011 (up to 50% packing efficiency by volurre)

Compressive Strength = 205 psi

5. Mixture of Mixed Bed Ion Exchange Bead Resin and 24% Boric Acid solution (80% packing efficiency). Full scale 55 gallon drums use 2151bs '

of ENVIROSTONE, 2411bs of bead resin and 21 gallons of 24% boric acid i solution. l Compressive Strength = 83 psi l 10

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6. -Mixture of Powdered Ion Exchange Resins ar.d 24% Boric Acid solution (83% packing efficiency). Full scale 55 gallon drums use 1951bs of-ENVIROSTONE, 150lbs of powdered resin and 31 gallons of 24% boric acid solution.

Compressive Strength = 63 psi

7. EDTA decontamination fluid (up to 50% packing efficiency by volume of 50% EDTA solution Compressive Strength = 1485 psi

8. A Neat Aqueous Mixture of ENVIROSTONE Gypsum Cement Compressive Strength = 1280 psi All of the waste streams meet or exceed the 60 psi currently recomended for waste forms.

2.3.4 Thermal Cycling:

The thermal cycling test were performed on two' inch cubes according to ASTM B553 "Standard Test Method for Thenpal Cycling of Electroplated plastics".

Based on USG Corporation _ letter of September 9,1983 frcm Mr. Robert Lange to Mr. Leo Higginbotham of the NRC and a subsequent NRC response to that letter (dated September 30,1983)(bothcontainedinref4)itwasagreedthatsince USG has equipment limitations and would not be able to perform a thermal cycling test from -40 to 60 degrees centigrade as recomended in the technical position on waste form; it would be acceptable to perform the test from -20 to 60 degrees centigrade if the number of thermal cycles was increased from thirty to fif ty. The compressive strength after thermal cycling should be at least 60 psi. The following are the results of the compressive strength tests after thermal cycling for the eight waste streains at the maximum proposed ,

packing efficiencies:

1. 24% Boric Acid Solutions (up to 78% packing efficiency by volume) i Compressive Strength = 171 psi

2. Unexpended Mixed Bed Ion Exchange Bead Resin (up to 80% packing efficiency by volume) ,

l Compressive Strength = 176 psi l

3. Unexpended Powdered Ion Exchange Resin (up to 82% packing efficiency l byvolume)

Coinpressive Strength = 223 psi

4. Lubrichting 011 (up to 50% packing efficiency by volume) 11 l

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Compressive Strength = 225 psi

5. Mixture of Mixed Bed Ion Exchange Bead Resin and 24% Boric Acid-solution (80% packing efficiency). Full scale 55. gallon drums use 2151bs of ENVIROSTONE, 2411bs of bead resin and 21 gallons of 24% boric acid solution.

Compressive Strength = 68 psi Data on compressive strengths for this waste stream were provided in USG'.s second response dated July 2, 1986 (ref 10). The data presented is for eight cubes that were tested under thermal cycling. The average compressive strength as inoicated is 68 psi. However, three of the samples had compressive strengths of 50, 53 and 58 respectively which are all under the reccuended value of 60 psi. Therefore, this waste stream is inconsistant with the recomendations of the Technical Position on Waste Form for the thermal cyling test and is unacceptable.

6. Mixture of Powdered Ion Exchange Resins and 24% Boric Acid solution (83% packing efficiency). Full scale 55 gallon drums use 1951bs of ENVIR0 STONE,150lbs of powdered resin and 31 gallons of 24% boric acid solution.

Compressive Strength = 91 psi

7. EDTA decontamination fluid (up to 50% packing efficiency by volume of 50% EDTA solution Compressive Strength = 1565 psi

8. A Neat Aquecus Mixture of ENVIROSTONE Gypsum Cement to Simulate Encapsulation of Solid Objects such as Used Equipment, Spent Filter Cartridges, etc. (up to 107 lb water per 100 lb binder)

Compressive Strength = 1474 psi All of the waste streams meet or exceed the 60 psi currently recomended for waste forms except the bead resin boric acid mixture (see no.5 above).

2.3.5 Biodegradation 2.3.5.1 Funga_1 Growth Waste forms solidified frcm ENVIR0 STONE were evaluated for resistance to fungal growth per ASTM "Standard Practice for Determining Resistance of Synthetic Polymeric Material to Fungi". The Technical Position on waste form recomends that there should be no visible fungal growth following the biodegradation tests and that the specimens should have a compressive strength of at least 60 psi. The following are the results of the fungal tests and the compressive strengths for the eight waste streams at their maximum proposed packing efficiencies:

1. 24% Boric Acid Solutions (up to 78% packing efficiency by volun;e) 12

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Fungal growth - No Growth Compressive Strength = 269 psi

2. UnexpendedMixedBedIonExchangeBeacResin(upto80% packing efficiency by volume)

Fungal Growth - No Growth Compressive Strength = 228 psi

3. Unexpended Powdered Ion Exchange Resin (up-to 82% packing efficiency by volume)

Fungal Growth _- No Growth Compressive Stroagth = 241 psi

4. Lubricating 011 (up to 50% packing efficiency by volume)

Fungal Growtn - Heavy Growth Compressive Strength = 938 psi

5. Mixture of Mixed Bed Ion Exchange Bead Resin and 24% Boric Acid solution (80% packing efficiency)._ Full scale 55_ gallon drums use 2151bs of ENVIR0 STONE, 2411bs of bead resin and 21 gallons of 24% boric acid solution.

Fungal Growth - No Growth Compressive Strength = 114 psi

6. Mixture of Powdered Ion Exchange Resins and 24% Boric Acid solution (83% packing efficiency). Full scale 55 gallon drums use 1951bs of ENVIROSTONE, 150lbs of powdered resin and 31 gallons of 24% boric acid solution.

Fungal Growth - No Growth Compressive Strength = 126 psi I

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7. EDTA decontamination fluid (up to 50% packing efficiency by volume of l 50% EDTA solution  !

Fungal Growth - No Growth ,

Compressive Strength = 1510 psi l

8. A Neat Aqueous Mixture of ENVIR0 STONE Gypsum Cement Fungal Growth - No Growth i Compressive Strength = 1433 psi  !

All of the waste streams except except "Lubricating Oil" meet the recommendation of the Technical Position on Waste Form on Fungal exposure.

USG corporation has perfonred additional testing on the Lubricating Oil waste stream in order to demonstrate that the fungal growth does not impact 13

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significantly the compressive strength of the solidified waste product. The testing performed on the Lubricating oil waste stream consisted of the following:

a. Three batches of samples were prepared (12 samples each at 30%,

40%, and 50% packing efficiencies)

b. Six of each waste stream were used as control samples and the other six were inoculated as per ASTM G-21

c. At the end of three weeks, all cubes were removed and lightly sponged to remove the fungal growth.

d. A portion of the samples were. reinoculated and after a second three week period were lightly scrubbed to remove fungal growth and the cubes were then tested for density and conpressive strength.

The results of the fungal tests indicated heavy growth on the test specimens at each of the three packing efficiencies. The technical position on waste form recomends that if growth is observed following the extraction procedure, longer term testing should be performed to determine the extrapolated biodegradation rate for a 300 year period. Since no such long term test was performed, and the fungal growth rate had a rating of 4 (heavy) after the extraction was performed, it is not possible to approve the lubricating oil weste stream.

2.3.5.2 Bacterial Growth Waste forms solidified from ENVIR0 STONE were evaluated for resistance to fungal growth per ASTM G-22 "Standard Practice for Determining Resistance of Plastics to Bacteria". The Technical Position on Waste Form recomends that there should be no visible bacterial growth. The specimens should also have a compressive strength of at least 60 psi. The following are the results of the fungal tests and the compressive strengths for the eight waste streams at their maximum proposed packing efficiencies:

1. 24% Boric Acid Solutions (up to 78% packing efficiency by volume)

Bacterial growth - No Growth Compressive Strength = 259 psi

2. Unexpended Mixed Bed Ion Exchange Bead Resin (up to 80% packing efficiency by volume)

Bacterial. Growth - No Growth Compressive Strength = 225 psi

3. Unexpended Powdered Ion Exchange Resin (up to 82% packing efficiency by volume)

Bacterial Growth - No Growth Compressive Strength = 263 psi 14

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4. Lubricating Oil (up to 50% packing efficiency by volume)

Bacterial Growth - No Growth Compressive Strength = 235 psi

5. Mixture of Mixed Bed Ion Exchange Bead Resin and 24% Boric Acid solution (80% packing efficiency). Full scale 55. gallon drums use 2151bs of ENVIROSTONE, 2411bs of bead resin and 21 gallons of 24% boric acid solution.

Bacterial Growth - No Growth Compressive Strength = 129 psi

6. Mixture of Powdered Ion Exchange Resins and 24% Boric Acid solution (83% packing efficiency). Full scale 55 gallon drums use 1951bs of ENVIROSTONE, 150lbs of powdered resin and 31 gallons of 24% boric acid solution.

Bacterial Growth - No Growth Compressive Strength = 115 psi

7. EDTA decontamination fluid (up to 50% packing efficiency by volume of 50% EDTA solution Bacterial Growth - No Growth Compressive Strength = 1515 psi

8. A Heat Aqueous Mixture of ENVIROSTONE Gypsum Cement Bacterial Growth - No Growth Compressive Strength = 1368 psi All of the waste streams meet the recommendation of the Technical Position on Waste Fonn on bacterial exposure.

2.3.6 Leachability Index Each waste form was analyzed for leachability resistance as per ANS 16.1 -

"Measurement of the Leachability of Solidified Low Level Radioactive VJstes".

The leachant solutions used were deionized water and synthetic seawri2r. Each waste form was tested with four radioactive tracers Cs-137, Co-60, Ce-141, and Sr-85. The Technical Position on Waste Form reccavends that the leach index for each of the tracers be at least 6.0 and the length of the tests should be 90 days. The following are the leach indices for each of the the proposed waste streams at their maximum packing efficiencies:

1. 24% Boric Acid Solutions (up to 78% packing efficiency by volume)

Sample No.- 7 Deionized water 15

c Ce-141 = 8.6 Sr-85 = 7.7 Cs-137 = 5.8 Co-60 = 5.7

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Seawater Ce-141 = 7.9 Sr-85 = 7.4 Cs-137 = 5.8 Co-60 = 5.9 The waste stream containing the 24%' Boric acid solution does not meet the recomendation as stated in the technical position that the leach index should be at least 6.0. In addition the data presented at 70% packing efficiency (sample 6) also contains leach indices for Cesium and Cobalt which are below 6.0. Therefore, this waste stream is inconsistent with the recommendations of the Technical Position on Waste Form and is unacceptable.

2. Unexpended Mixed Bed Ion Exchange Bead Resin (up to 80% packing efficiency by volume)

Sample No.- 3 Deionized water Ce-141 = 10.2 Sr-85 = 8.2 Cs-137 = 6.9 Co-60 = 8.5 Seawater Ce-141 = 10.6 Sr-85 = 7.4 Cs-137 = 6.5 Co-60 = 7.1 The results for the leach test for this waste stream meets or exceeds the recormended value of 6.0 as stated in the Technical Position of Waste Form.

3. Unexpended Powdered lon Exchange Pesin (up to 82% packing efficiency by volume)

Sample No.- 5 Deionized water Ce-141 = 9.3 Sr-85 = 7.7 '

Cs-137 = 6.0 Co-60 = 8.0 l I

Seawater Ce-141 = 8.4 Sr-85 = 7.4 l Cs-137 = 5.9 Co-60 = 7.1 i The waste stream containing the powdered ion exchange resin is inconsistent with the recomendation as stated in the technical position that the leach index should be at least 6.0. In addition the data presented at 78% packing efficiency (sample 4) also indicates a leach index on 5.9 for Cesium in  ;

seawater. Therefore, this waste stream is inconsistent with the l reconirendations of the technical position on waste form and is unacceptable.

4. LubricatingOil(upto50%packingefficiencybyvolume)

Sample No.- 12 16

Deionized water Ce-141 = 9.0 Sr-85 = 8.2 Cs-137 = 6.8 Co-60 = 7.8 Seawater Ce-141 = 8.7 Sr-85 = 8.1 Cs-137 = 6.6 Co-60 = 7.7 The results for the leach test for this waste stream meets or exceeds the recommended value of 6.0 as stated in the Technical Position of Waste Form.

5. Mixture of Mixed Bed Ion Exchange Bead Resin and 24% Boric Acid solution (80% packing efficiency). Full scale 55 gallon drums use 2151bs of ENVIR0 STONE, 2411bs of bead resin and 21 gallons of 24% boric acid solution.

Sample No - 8 Deionized water Ce-141 = 9.1 Sr-85 = 8.0 Cs-137 = 6.5 Co-60 = 7.1 Seawater

, Ce-141 = 8.7 Sr-85 = 7.3

! Cs-137 = 6.1 Co-60 = 6.4 The results for the leach test for this waste stream meets or exceeds the recommended value of 6.0 as stated in the Technical Position of Waste Form. i 1

6. Mixture of Powdered Ion Exchange Resins and 24% Boric Acid solution (83% packing efficiency). Full scaleuS5 gallon drums use 1951bs of ENVIROSTONE, 150lbs of powdered resin and 31 gallons of 24% boric acid solution.

l Sample No.- 9 Deionized water Ce-141 = 8.8 Sr-85 = 7.6 Cs-137 = 5.8 Co-60 = 6.5 Seawater Ce-141 = 8.4 Sr-85 = 7.2 Cs-137 = 5.7 Co-60 = 6.3

)

l The waste stream containing the powdered ion exchange resin and boric acid is inconsistent with the recomaendation as stated in the technical position that the leach index should be at least 6.0 and is therefore, unacceptable.

7. EDTA decontamination fluid (up to 50% packing efficiency by volume of 50% EDTA solution Sample No.- 10 17

4 Deionized water Ce-141 = 8.4 Sr-85 = 8.2 Cs-137 = 5.7 Co-60 = 5.8 Seawater Ce-141 = 8.3 Sr-85 = 7.9 Cs-137 = 5.7 Co-60 = 5.9 The waste stream containing EDTA decontamination fluid is inconsistent with the recommendation as stated in the technical position that the leach index should be at least 6.0 and is therefore, unacceptable.

8. A Neat Aqueous Mixture of ENVIROSTONE Gypsum Cement Sample No.- 1 Deionized water Ce-141 = 9.5 Sr-85 = 7.9 Cs-137 = 6.2 Co-60 = 6.3 Seawater Ce-141 = 9.2 Sr-85 = 7.6 Cs-137 = 6.0 Co-60 = 6.2 The results for the leach test for this waste stream meets or exceeds the recommenced value of 6.0 as stated in the Technical Position of Waste Form.

The following are the waste streams that meet or exceed the recommended leach indices as stated in the technical position on waste form (a value of 6.0).

1. Unexpended Mixed Bed Ion Exchange Bead Resin (up to 80% packing efficiency by volume) 2*. Lubricating Oil (up to 50% packing efficiency by volume) 3**. Mixtures of Mixed Bed lon Exchange Bead Resin and 24% Boric Acid solution (up to 241 lb (dry weight) resin /21 gallon acid solution per 55 gallon drum) 4 A Neat Aquecus Mixture of ENVIROSTONE Gypsum Cement to Simulate Encapsulation of Solid Objects such as Used Equipment, Spent Filter Cartridges, etc. (up to 107 lb water per 100 lb binder)

• This waste stream did not pass the biodegradation test.

• • This waste stream did not pass the thermal cycling test.

2.3.7 Free liquid Liquid wastes are canpletely solidified during normal operations and thus satisfy the requirement of no more than 0.5% by volume of free standing liquid.

No free liquids were observed during the qualification testing.

1 i

18

2.3.8 Full scale results The Technical Position on Waste Form recomends that if simulated laboratory specimens are used for testing of the waste form, then test data from cores of full scale samples should be obtained to correlate the characteristics of both the lab and full scale samples.

A full scale evaluation of each waste stream was performed at the maximum proposed packing efficiencies using 55 gallon drums (full size). In addition a portion of the slurry from the 55 gallon drum samples was used in order to determine initial compressive strength, compressive strength after 90 day imersion and density vs. strength correlations.

USG also performed full scale destruccive testing on 55 gallon druns for two waste streams ai neat and b) Lubricating oil at a 50% packing efficiency. A control sarrple was taken from the slurry and gang cubes samples were taken from the top, middle and bottom of the 55 gallon drum sample. Initial densities and compr ssive strengths were determined after seven days. Final densities and compressive strengths were tested after 90 days of water imersion.

The results of the testing of the neat waste stream indicated a compressive strength over the current recomended value of 60 psi. Correlation between the full scale tests and the slurry samples for initial testing and the 90 day imersion were within 10% and are acceptable.

The results of the testing of the Lubricating oil waste stream indicate that the product exceeds the recomended value of compressive strength of 60 psi.

The compressive strengths within the container were within 5% of each other and exceed the control sample by 20%. After im ersion testing the compressive strengths within the container were within 20% and exceeded the control sample by 20%. Correlation was demonstrated within the limits stated above and is acceptable.

A correlation of densities versus compressive strength for the full scale samples appears reasonable based on the data contained in the topical report (ie., increased density equals increased ccmpressive strength).

The full scale results are applicable only for in-drum mixing. Other methods such as tumble or in-line mixing have not been tested.

2.3.9 Horroceneity Full scale samples were prepared for each of the proposed waste streams at their maximum packing efficiencies. After solidification of each waste form, the drums were destructively analyzed to ensure a homogeneous cast. Each drum was sawed open and three saiaples were taken to compare censities from the top, middle, and bottcm of the full scale 53mple with density data from bench scale mixes. Based on the densities reported for the full scale samples for all of the waste streams, (note that the mixed bed resin / boric acid waste stream failed the compressive test for thermal cyling) horogeneity was achieved in that all ccepressive strengths were above the recomended 60 psi minimum.

2.3.10 Process Control Program 19

The Technical Position on Waste Fom recommends that implementation of the guidance on stability presented in the technical position be performed through a qualified process control program. Periodic demonstrations that the solidification system is functioning properly are recommended.

The process centrol program presented by USG (ref 9, 13) gives guidance to waste generators on how to transport, handle, store, and mix the waste steams with ENVIROSTONE. In addition, it discusses mixing parameters and quantities of ENVIROSTONE, emulsifier and wastes needed to maintain a given packing efficiency. The generic process control program proposed by USG is satisfactory and should ensure that the solidified product meets the stability reouirements of 10 CFR Part 61.

2.3.11 Cure Conditio_ns The NRC through its contractor Brookhaven National Laboratories has investigated the effects of cure conditions on the stability of the ENVIR0 STONE waste form.

The purpose of this investigation was to examine the effects of curing conditions on the stability of cement solidified ion exchange resins upon imersion in water. Test specimens were prepared by solidifying a typical ion exchange resin mixture using vendor supplied formulations and a formulation from the literature as reference. Samples prepared using each fomulation were curec for different times under different conditions prior to imersion in water. The perfomance of the samples was monitored throughout the imersion period and the compressive strengths were measured at the end of the the immersion test. Results for these tests for ENVIROSTONE are as follows:

No spalling of cracking was observed on any of the ENVIROSTONE Gypsum Cement samples af ter 90 days imersion in water. However, during the first week of immersion, it was cbserved that the surfaces of waste foms cured for 7 and 14 days in sealed containers had softened such that the plastic tcogs used to move the samples had caused chipping of the surface. It was also noticed that the ENVIROSTONE forms were no longer completely rigid after 90 days of imersion. The soft outer shell that appeared on the samples could easily be removed frcm the waste form. The ENVIROSTONE foms also lost a small number of resin beads as if a bead would swell and pop cut of the surface.

Cure time did not appear to affect the final mechanical strength of ENVIROSTOME Gypsum Cement af ter imersion in water. In addition the ENVIROSTONE Gypsum Cement samples had compressive strengths greater than 60 psi but the forms had softened significantly.

The Technical Position on Waste Form does not mention softening of waste form as an adversa condition for a solidified waste form. However, the NRC is concerned that softening could lead to a waste form that does not maintain its structural stability. USG has performed compressive strength I tests on the ENVIROSTONE waste fom after immersion (wet samples). The results of these tests indicate that the compressive strength is greater than the recomended 60 psi and therefore is acceptable with respect to the Technical Position on Weste Form. However, based on the uncertainty of l l

I 20

l 4

the long term effects of softening of gypsum cement, the maximum loading should be reduced to 60% pacing efficiency from 80%. This will increase confidence that ENVIROSTONE will maintain long term stability. In the future, if it is indicated that softening of ENVIROSTONE will result in a waste form that does not maintain structural stability, then the conclusions regarding acceptability of ENVIROSTONE will need to be reevaluated. The NRC therefore can provide only a one year conditional approval of ENVIROSTONE subject to limitations stated elsewhere in this TER and will reevaluate the acceptability of.ENVIROSTONE after further study.

3.0 REGUI.ATORY POSITION The topical report entitled "ENVIROSTONE Gypsum Cerrent, USG-684-1" contains eight different proposed waste streams. Following is surrerary of the results of the evaluation of the different, waste streams versus the recommendations of the Technical Position on Waste Form:

1. 24% Boric Acid Solutions (up to 78% packing _ efficiency by volurre)

Fails leachability test

2. Unexpended Mixed Bed Ion Exchange Bead Resin (up to 80% packing efficiency by volume)

Satisfactory (but limited to 60% packing efficiency; see

, table 1)

3. Unexpended Powdered Ion Exchange Resin (up to 82% packing efficiency by volume)

Fails leachability test

4. Lubricating Oil (up to 50% packing efficiency by volume)

Fails Fungal test

5. Mixture of Mixed Bed Ion Exchange Bead Resin and 24% Boric Acid solution (80% packing efficiency). Full scale 55 gallon drums use 2151bs of ENVIR0 STONE, 2411bs of beaa resin and 21 gallons of 24% boric acid solution.

Fails Thermal cycling test

6. Mixtures of Pcwdered Ion Exchange Resins and 24% Boric Acid solution )

(83% packing efficiency). Full scale 55 gallon drums use 1951bs of l ENVIR0 STONE, 150lbs of powdered resin and 31 gallons of 24% boric acid snlution. ,

i

! Fails leachability test I I l 21 L

.b

C

7. EDTA decontamination fluid (up to 50% packing efficiency by volume of 50% EDTA solution Fails leachability test

8. A Neat Aqueous Mixture of ENVIR0 STONE Gypsum Cement Satisfactory Table 1 contains a list of the acceptable waste streams as well as the maximum packing efficiencies allowed (by volume).

The USG topical report, USG-684-1, and USG's responses dated July 2,1986 and July 17, 1987 to NRC's questions and comments are acceptable as a reference document for licensing the waste fonns produced with ENVIROSTONE, subject to the following limitations:

1. Waste streams and packing efficiencies are limited to those shown in table 1.

2. The waste forms produced are limiteJ to those made from the waste streams specifically identified in the topical report as those used to prepare the test specimens on which the data were obtained.

3. The waste forms will be contained in 55 gallon drums.

4. The process control program outlined in the topical report is followed.

5. A design for encapsulation of waste was not presented in the topical report and therefore no specific types of encapsulation can be approved.

6. Conditional one year opproval is given based on the uncertainties regarding softening of the waste form and discussed in section 2.3.11.

With respect to the above conclusions, the ENVIROSTONE waste form should be capable of meeting the stability requirements of 10 CFR Part 61 when produced using the process control program (limited to in drum mixing) described in the topical report.

22

~

I p 43 , I*

Table 1-P dBedIonExchangeBeadResin(upto60% packing effic e c vlue) 2 A Neat Aqueous Mixture of ENVIROSTONE Gypsum Cement to Simulate Encapsulation of Solid Objects such as Used Equipment, Spent Filter Cartridges, etc. (up to 107 lb water per 100 lb binder). However, a design fo, encapsu'ation of waste was not presented in the topical report and therefore no specific types of encapsulation can be approved.

7 i

23

_ _ _ _ _ _ . - 2

, , k ., i b l

I i

i References

1. Licensing Requirunents for Land Disposal of Radioactive Waste,10 CFR Part )

61, Revised as of January 1, 1985.

2. Technical Position on Waste Form, Rev. 0, May 1983, Low-level Waste Licensing Branch, Division of Waste Management, U.S. Nuclear Regulatory Commission, Washington, D.C.

3. Measurement of the Leachability of Solidified Low-level wastes, ANS-16-1, American Nuclear Society, June 20, 1984.

4. Topical Report Entitled "ENVIROSTONE Gypsum Cement 10 CFR 61 Compliance  :

Testing", USG-684-1, May, 1984, USG Corporation

5. NRC letter to USG acceptinc submittal of USG-684-1, June,1984

6. NRC connents on USG topical report, Memo to Lange from Higginbotham, September 13, 1985. .

7. Connents from South Carolina on ENVIROSTONE gypsum cement topical report, March, 1985

8. Concents from Washington on ENVIR0 STONE gypsum cement topical report, July, 1985

9. USG draft responses on NRC questions on USG-684-1, November, 1985

10. USG responses to NRC's Convents, Memo from.Rosensteil to Tiktinsky, July 2, 1986.

11. Second set of questions to USG from NRC, October 27, 1987.

12. USG secer.d set of responses to NRC, July 17, 1987.

13. Revised PCP for ENVIROSTONE, Sept. 24, 1987

14. Letter from USG to NRC on durability of gypsum cement, Oc+.ober 8, 1987 24

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